题目2单选题
某免疫指标在人群中为正态分布,制定其正常值范围通常用A. <img src="https://tihai-oss-cloud.itihey.com/img/e6afee9933abe85b40d97e779cac7d0a.jpg">±1sB. <img src="https://tihai-oss-cloud.itihey.com/img/336d1923d088bd0f818448365d98caf1.jpg">±2sC. <img src="https://tihai-oss-cloud.itihey.com/img/990894f6dab0eaef86ca8bd59edf015f.jpg">±3sD. <img src="https://tihai-oss-cloud.itihey.com/img/512cbcf3122a72e3b2f60d55bfc29c23.jpg">±4sE. <img src="https://tihai-oss-cloud.itihey.com/img/4a8baad134d1c31a6a5cab3f7281eff9.jpg">±5s